1. Field of the Invention
The present invention relates to a cable duct device for a rack, and more particularly to a cable duct device for a rack having a configuration capable of allowing cables to be easily received in an arranged state in the rack and to be easily released therefrom, without using no separate cover.
2. Description of the Prior Art
Typically, communication equipment, for example, an exchanger, includes a rack having a cabinet shape, a plurality of printed circuit boards mounted on a shelf formed in the rack, a mother board combined with the printed circuit boards, and a number of cables interconnecting a communication circuit in the shelf with subscribers.
The cables are collected at a side of the rack and bound with strips. Alternatively, several bundles of the cables are respectively put in a cable duct device which is fixed to the rack.
One conventional cable duct device includes a duct and a cover. A bundle of cables is held in the duct, and then the cover is coupled to the duct. Typically, the duct and cover are made of a synthetic resin material.
The duct includes a pair of bent plates each having an L shape. Each of the bent plates has a plurality of slots at one wall thereof. The walls of the bent plates formed with the slots face each other. Tension portions are formed at both ends of the duct corresponding to respective free ends of the bent plates.
The duct cover is provided at both ends thereof with coupling portions, respectively. The coupling portions have an inwardly bent shape. The coupling portions of the duct cover are engaged with the tension portions of the duct, so that the duct cover is coupled to the duct.
Where cables are held in a rack by use of the above mentioned conventional cable duct device, however, there is a problem in that a degradation in workability occurs in processes for an installation of additional cables in the rack or a repair of the rack because the duct cover must be separated from the duct. Furthermore, the appearance of the duct device is degraded due to the cables held therein because there is no structure for holding the cables in good shape within the cable duct device.
Furthermore, there is a problem in that the conventional cable duct device exhibits a degraded stability. For example, after an earthquake-proof test conducted for the conventional cable duct device, it can be found that the duct cover is very easily separated from the duct even when a small amount of external impact is applied to the cable duct device.
Other examples of cable holding devices are seen, for example, in the following U.S. Patents. U.S. Pat. No. 5,683,001, to Masuda et al., entitled Rack For Mounting Electronic Apparatuses, describes a rack with C-shaped posts whose recesses are used as cable ducts. U.S. Pat. No. 5,728,976, to Santucci et al., entitled Detachable cover For Wire Ducts Having A Living Hinge, describes a cable duct system having a hinged cover. U.S. Pat. No. 5,929,381, to Daoud, entitled Signal Transmission Media Routing Arrangement With Rectangular Distribution Rings, describes an arrangement having external troughs for guiding wires. The exterior trough has a frame having an opening for inserting a wire. U.S. Pat. No. Design 402,264, entitled Cable Duct, illustrates a cable duct having a cover portion and a base portion, with the cover portion apparently held by tension in the base portion.
Based on our reading of the art, we have decided that what is needed is a cable duct device which does not suffer from the above problems.